Centrifugal separator



April 5, 1938. H. E. ELR-OD Y 3,1

CENTRIFUGAL SEPARATOR Filed Aug. 13, 1935 2 Sheets-Sheet l Patented 5, 1933 g I 2,1

UNITED STATES PATENT OFFICE CENTRIFUGAL SEPARATOR Henry E. Elrod, 1mm, Tex. Application August 13, 1935, Serial No. 36,025

5 Claims. (01. 233-20) This invention relates to improvements in central opening 22 formed by a curved-over centrifugal separators and its principal object is flange 24. Within the opening 22 is a sleeve 26 to provide a machine of this kind which will secured by a flange 28 to a spider 30, which is operate successfully upon mixtures in which the fixed by a hub 3| to shaft l6. Extending out- 5 ratio of lighter to heavier substance varies conward from the spider 30 is a diaphragm 32, siderably. which may be in the form of a solid or perforated My invention is intended for centrifugal sepaplate or may consist of radiating arms, The rators for treating mixtures in which there is a material to be separated is supplied through a substantial difference in opacity between the pipe 34 to the space within sleeve 26 and pours light substance and the heavy substance. Mixdown through this sleeve into the bottom of the 10 tures of'solid and liquid, such as wet sludge, are bowl, whence it travels out under the diaphragm typical examples of the kind of materials for 32 toward the periphery of the bowl and there which separators according to my invention are deposits the heavier material, the lighter liquid suited. flowing inward over the top of the diaphragm 32 The essential novel feature of my invention is and out through the opening 22. As the lighter 5 the use of a light responsive device arranged to liquid is discharged from the lip 24 it is caught sense the transition zone between the lighter by a trough 36 and led off through an outlet 38. and heavier substances, whereby when the ac- Means are provided to discharge the heavier cretion of the heavier substance reaches a certain material from the periphery of the bowl. In

limit, outlet means for the heavier substance can the machine shown in these figures, the periphbe operated, preferably under the direct control cry of the bowl is in the shape of four eccentric of the light responsive means, to discharge some curves 40 connected by radial steps 42. In these of the heavier substance. The machine can be radial steps are discharge openings 44 normally arranged to regulate the outlet means to hold the covered by gates The gates y e un d as transition zone nearly stationary; or to operate upon weighted arms 48 pivotally connected to nthe outlet means intermittently, rapidly dischargthe casing of the bowl at 50 and bearing at the ing a considerable amount of the heavier subend on the far side of the pivot from the gate a stance and then allowing it to build up again. weight 52. The opposite end of each lever 48 The invention can be embodied in many difieris Connected y a link 54 t t e iddle of a cut forms, some of which are shown in the aclever the lower end of Which is p OOII- 30 companying drawings, wherein: nected to the bottom of the bowl at 58 and the Figure 1 is a plan view partly in section of a upp end of which (Berries a r0116! bearing centrifugal separator according to the invention, against a cone B2. The cone 62 is connected by Figure 2 is a vertical section of the same sepa spline 64 to shaft lli so as to be slidable therearator taken substantally upon a plane passing A ov 55 n c 5 is engaged by a roller 35 through the axis of the separator, parts being 8 mOImted up n a lever 12 pivoted at 14 to the however shown in elevation which would actually frame The pp d f lever 12 is articube cut by the plane, lated at 16 to the connecting rod 18 of a piston Figure 3 is a wiring diagram, and 80 sliding in a cylinder 82 mounted upon the 10 Figures 4, 5, and 6 are fragmentary sectional cross bar l2. The piston 80 is normally held in views of a portion of the separator bowl showp Position y a Spring 84 a d s orced down ing various arrangements of the optical control Ward by Compressed air admitted to the y der means, 82 by a pipe 86 under the control of means pres- In the form of the invention shown in Figures ently to be de ibed.

1-3, th re is mounted between a base plate In When the separator is rotating, the weighted 45 and the cross piece I2 of an upright frame l4 levers 48 attached to the gates 46 tend to swing a shaft IE to which is fixed by a hub I! a' sepaclockwise, under the influence of weights 52, to rator bowl 18. This bowl is shown as having a. withdraw the gates 46 from discharge openings greater diametrical than axial extension and this The le rs a r r n by t e, action of is the preferred shape of bowl for the purpose of the cone 62 upon levers-56 and links 54 when the 50 the invention. The shaft and bowl can be spun cone is in its lower position, but when the cone is by means of a pulley 20 driven by a belt (not raised to the position shown in Figure 2, the shown). The bowl may conveniently be made in levers 56 are allowed to swing inward under the two flanged halves secured together by bolts l9. influence of the weights 52 and open the gates.

At its upper side, the separator bowl "has 9. There are four of the gates 46 and their appur- 55 tenant control devices and when they are all opened together, the solids which have collected in the periphery of the bowl are discharged into a trough 99 and drain ofl through an outlet 99.

According to the preferred form. of the invention the gates 40 are to be directly controlled by light sensitive means arranged to sense the position of the transition zone between the heavier material accumulating in the periphery of the bowl and the lighter liquid. Figures 1-3 show one arrangement of such control means. There is mounted upon the diaphragm 92 a ring shaped reflector 92, which faces a group of windows 94 arranged in a circle in the upper wall 99 of the separator bowl. Opposite the ring of windows 94', there is mounted upon the cross bar I2 of the frame I4 a light sensitive cell 99, such as a phototube. This tube is influenced by light reflected from the reflector 92 through the windows 94 and is adjusted to change the condition in a control circuit when the fluid passing over the reflector 92 becomes murky, indicating that the transition zone between the heavier material deposited in the periphery of the separator bowl is encroaching upon the reflector.

As shown in Fig. 3, the piston 90 is operated by compressed air supplied from a pipe 99 under the control of a valve I00. This valve is normally held by a spring I02 in position to connect the space above piston 90 in cylinder 92 with relief port I04 open to the atmosphere. The valve is moved by a solenoid I06 to position to close the relief port and connect the cylinder 82 with the compressed air supply. The solenoid I09 is connected to a supply of alternating current I09 by a switch IIO controlled by a relay H2, H4. The coil Ill of the relay is connected in the plate circuit of an amplifier tube I It, in the grid circuit of which is the phototube". A

transformer I I9 supplies the current which'maintains the voltage in the several circuits of the amplifier tube II6. A potentiometer I20 permits adjustment of the normal grid voltage to adapt the control circuit to the range of intensity of the light beam striking the phototube 99.

'When the light striking the phototube 99 is reduced by the reflector 92 being covered by the heavier material, the voltage drop across the phototube is increased and the grid voltage of tube H6 is made more negative, thus reducing the plate current. This permits the relay H2 and switch IIO to assume the position shown in Fig. 3, thus opening the circuit of solenoid I09 and allowing the valve I to swing to the position shown. The air in cylinder 82 is exhausted to the atmosphere and piston 90 rises, raising the ,cone 92. The levers 58 are allowed to swing inward under the influence of weighted levers 48, which opens the gates 46. In the position shown in Fig. 3 switch IIO may close a circuit I09 containing an alarm or indicating device such as electric lamp Ill. When enough of the heavier material has been discharged through the gates to uncover the reflector 92, the beam of light striking phototube 99 reduces the voltage drop across the phototube and makes the voltage of the grid less negative. This increases the plate current and causes the relay H2, H4 to close switch IIO, operating solenoid I06 and throwing valve I00 to position to connect the compressed air supply to cylinder 92. The piston 80 is forced down and presses cone 92 downward, thrusting levers 56 outward and closing the gates 49.

An artificial source of light may be provided to project the light beam which is reflected from reflector 92 to phototube 99. In this case the phototube and source of light may both be mounted directly on the separator bowl, as shown in Fig. 6. In this flgure the source of light is indicated at I22 and phototube at I24. These being mounted on the bottom wall of the separator bowl, reflector 92 faces downward. The light source and phototube can be connected through collector rings (not shown) with the control circui The reflector can be dispensed with in the form of invention shown in Fig. 4. In this case, a phototube I29 is mounted upon diaphragm l2 and a source of light I29 shines through a window Itlupon the phototube.

Fig. shows still another modification wherein the reflector is again dispensed with by mak ing the light beam travel from a source of light I22 through a window I 34 across the critical zone of the separator bowl, through a window I99 to phototube I28. In all these cases the heavier solids building up in the periphery of the separator bowl interrupt the beam of light and therefore increase the voltage drop across the phototube.

The invention is susceptible of many modifications, the forms shown being merely illustrative.

Having described my invention, I claim:

1. In a centrifugal separator, a rotary bowl, a reflector mounted in said bowl between the axis and the periphery thereof, window means in the wall of said bowl for admitting light to said reflector, light responsive means facing said reflector through said window means, means for guiding the mixture to be separated into said bowl behind said reflector, variable outlet means for the heavier substance, and means whereby said outlet means is operated under the control of said light responsive means to release the. heavier substance when said reflector is obscured thereby. Q

2. In a centrifugal separator, a rotary bowl of greater diametrical than axial extension, window means in the wall of said bowl within a zone between the axis and the periphery of said bowl, means for sensing through said window means the position of the transition zone between the lighter and heavier materials being separated, and discharge means for the heavier materials controlled by said sensing means.

3. In a centrifugal separator, a rotary bowl, normally closed outlet means for discharging the heavier substance from said bowl, reflecting means located within a zone in said bowl which is to be the limit of accretion of the heavier substance, means for illuminating said reflecting means, light responsive means under the influence of light reflected from said reflecting means, and means controlled by said light responsive means for opening said outlet means when said reflector becomes obscured by accretion of the heavier substance.

4. In a centrifugal separator, a rotary bowl having two opposite walls extending outward at a large angle to the axis of the bowl, light responsive means facing one of said walls, means including opposed windows in said walls for transmitting a beam of light through said bowl to said light responsive means across the zone which is to be the limit of accretion of the heavier substance, and outlet means for the heavier substance controlled by said light responsive means. 5. In a centrifugal separator, a rotary bowl, outlet means for the heavier substance adjacent the periphery of the bowl, means operable during the rotation of the bowl to apply a force tending to open said outlet means, means operable to close said outlet means and to hold the same closed against the action of said force applying means, photosensitive means for sensing the transition zone between the heavier and lighter substance, and means controlled bysaid photosensitive means to withdraw said closing means when the heavier substance is interposed in the zone of influence of said photosensitive means and to restore said closing means to operative position when the heavier substance passes out of the zone of influence of said photosensitive means.

HENRY E. ELROD. 

